Par is more important than total lumens...a 100k lumen bulb could outperform a 150k bulb if the par is higher...

a general rule is mh for veg and hps for flower as the blue promotes stem/leaves and the hps promotes bud/flower

hps throughout the grow is decent

hps with enhanced or wide spectrum (added blue) is better

mh for veg and hps for flower is better still

and the best is both mh and hps throughout....ie 400mh and 600hps

I've used a 400w hps hortilux bulb with great results so if you are only going to use one light I'd recommend a wide spectrum hps :jointsmile:
alwayssleepdeprived Reviewed by alwayssleepdeprived on . Kelvin - A little light on the subject. I'm sure there have been a few threads explaining a little about Kelvin, but I thought I'de confine the information into one area, expand on it a little, and go into some more detail. Here's a little information on Kelvin, from what I know: Kelvin temperature is a numerical measurement that describes the color appearance of the light produced by a lamp and the color appearance of the lamp itself, expressed on the Kelvin (K) scale. The science behind determining color temperature Rating: 5